Project Summary/Abstract Blood pressure (BP) of 140/90 mm Hg doubles the risk of cardiovascular diseases (CVD) and the total cost of hypertension reaches as high as $51 billion per year. Despite the enormous risk and cost associated with hypertension, less than half (48.3%) of hypertensive patients have a controlled blood pressure (BP) in the United States. Clinical trials demonstrated that a high rate of BP control (up to 85%) can be achieved with currently available therapies and strictly following recommended treatment protocols. This suggests that a higher proportion of uncontrolled BP could be explained by less aggressive treatment, poorer follow-up, and use of fewer or less effective drugs. The 2017 guideline for high BP management was recently published and lowered the threshold for the initiation of medication and definition of uncontrolled BP to BP ?130/80 mm Hg (from 140/90) for patients with CVD or higher risk of CVD. This challenges physicians to change their traditional hypertension management and could worsen the already low rate of compliance (range 25-65%) to hypertension treatment guidelines. Furthermore, conclusions from previous studies regarding compliance to older hypertension treatment guidelines were compromised due to failure to evaluate multiple aspects of hypertension care, such as comorbidities, follow-up and laboratory assessments; and use of subjective assessment such as physician self-report. The wide-spread adoption of electronic health record (EHR) technology and the vital patient information present in EHR data provide an exceptional opportunity to objectively evaluate several aspects of hypertension care, such as medications prescribed, laboratory procedures ordered, BP level achieved, follow-up monitoring examinations, demographic and comorbid information. We, therefore, propose to use the Northwestern Medicine Enterprise Data Warehouse (NMEDW) ? an integrated EHR database of health information from 2.9 million patients to 1) assess compliance to the 2017 hypertension management guidelines for 5 years since its release (2018-2022); 2) investigate whether patient?s age, race, body mass index, history of diabetes, CVD, chronic kidney disease, medication adherence, presence of health insurance and regular physician, and physican speciality predict level of compliance to the new treatment guideline; and 3) examine the association between level of compliance to the 2017 hypertension treatment guidelines and prospective patient BP trajectory over 5 years (2019-2023). Newly diagnosed hypertensive patients? demographics, BP, medications, lab results, follow-up visit, and comorbid conditions will be assessed from the NMEDW and will be compared to criteria developed based on the 2017 hypertension treatment guidelines to quantify compliance to the guideline. The proposed study provides the candidate an opportunity to learn EHR data-mining skills to assess association between compliance to the new hypertension treatment guideline and patient BP trajectory and to identify predictors of this compliance, as a first step, in designing future targeted interventions to enhance guideline compliance and BP control.